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Presentation on theme: "Nature provides us of many examples of self- assembled materials, from soft and flexible cell- membranes to hard sea shells. Such materials."— Presentation transcript:

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Nature provides us of many examples of self- assembled materials, from soft and flexible cell- membranes to hard sea shells. Such materials are the outcome of spontaneously formed complex structures due to molecular interaction between large collections of particles. In ChE, self assembled materials can provide an efficient method to organize molecules and molecular clusters into precise predetermined structures Simple, efficient methods to organize molecules and molecular clusters into precise, pre-determined structures are another important area of nanotechnology exploration. Nature provides many examples of intricately organized architectures such as sea shells -- whose self-assembly is choreographed by molecular interactions. Researchers are applying similar strategies to spontaneously organize new nanocomposite and mesoporous materials. In fact, these nanomaterials are already helping to attain scientists’ vision for new technologies.

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Nature provides us of many examples of self- assembled materials, from cell-membranes to … Colloidal and Molecular Self-Assembly Colloidal and molecular self-assembly may be used to build materials with spatially ordered patterns on the nanometer and sub-nanometer length scales. As a result of these short length scales involved, these materials may exhibit transport, electronic, optical, and mechanical properties different from homogeneous bulk material and are referred to as nanostructured materials. Professor Hillhouse’s research is focused towards understanding these self-assembly processes to engineer new nanostructured materials for solid- state electronic devices, fuel cells, and facilitated transport membranes. Nanostructured Materials A couple of examples of nanostructured materials are microporous and mesoporous molecular sieves. Unlike most other porous materials, which have broad pore size distributions and poorly defined pores, microporous and mesoporous molecular sieves are inorganic frameworks with pores of well-defined size, geometry, and connectivity. The pore diameters are tunable and are of molecular dimensions allowing the materials to exclude molecules based on size. As a result, powders of both microporous and mesoporous molecular sieves have found applications in catalysis and selective adsorption. However, if thin films of these materials could be synthesized with pores oriented perpendicular to a substrate, they may be used as templates for the deposition of nanometer scale electronic, magnetic, and thermoelectric materials. In this area our research is focused on the synthesis of new frameworks, controlling pore orientation, colloidal self-assembly, defect formation, growth of continuous thin films, and the synthesis of nanowires. Simple, efficient methods to organize molecules and molecular clusters into precise, pre-determined structures are another important area of nanotechnology exploration. Nature provides many examples of intricately organized architectures such as sea shells -- whose self-assembly is choreographed by molecular interactions. Researchers are applying similar strategies to spontaneously organize new nanocomposite and mesoporous materials. In fact, these nanomaterials are already helping to attain scientists’ vision for new technologies. Self-assembled materials exploit our understanding of molecular interactions and materials chemistry to enable the spontaneous formation of complex structures.

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The chemical engineering science of materials is entering a new era of so-called "designer materials," wherein, based upon the properties required for a particular application, a material is designed by exploiting the self-assembly of appropriately-chosen molecular constituents. Materials so fabricated (also sometimes referred to as advanced materials, are presently proposed for numerous applications, ranging from photonic and quantum devices to biomedical and tissue engineering applications. My research focus is to develop a theoretical and computonally-based program aimed at elucidating the fundamental mechanisms underlying the design of novel, self-assembled advanced materials. The goal is to complement the research of experimentalists (synthetic chemists, chemical engineers, and material scientists) by providing simple but quantitative guidelines to rationally design and synthesize these materials. Some of the current areas of interest include: Self-assembly of multicomponent functional block copolymers (FBP) like those containing semiconducting, optically active and liquid crystalline units has emerged as a promising route to advanced materials. Experiments reported in literature on these polymers have indicated that these FBPs exhibit novel hierarchical self-assembly morphologies dictated by an interplay between the steric and energetic interactions. To date however there does not exist any systematic way of predicting the morphologies (and thereby controlling the properties) of the above classes of polymers. The goal of the this project is to develop computational tools towards such an objective. In addition, the same tools can be extended to other systems involving similar features, like for instance, self-assembly in polymer-particle nanocomposites and synthetic blockcopolypeptides. An understanding of the dynamical features of self-assembled materials is a crucial prerequisite to any application involving processing of these materials. Theoretical descriptions of dynamics in these materials are inherently complicated due to the fact that: (i) These materials are complex fluids i.e. possess viscoelasticity (in contrast to simple Newtonian fluids whose descriptions are well developed); (ii) These materials are self-assembled, i.e. possess an inherent microstructure (in order). The latter feature contrasts with even conventionally studied complex fluids (like homogeneous polymer solutions). This poject proposes to develop computational descriptions for the dynamics of self-assembled phases of multiblock copolymers. The goal of this project is two-fold: (i) To explore the utility of mesoscale simulation tools, like dissipative particle dynamics (DPD) for predicting the dynamical response of self-assembled materials. (ii) To develop simple analytical descriptions of the dynamics of these materials to possibly enable a hybrid molecular+continuum scale simulations. The discovery of surfactant and liquid crystal templating techniques has enabled the controlled synthesis of mesoporous inorganic materials (possessing pore sizes in the range 20 A and 500 A). However, despite the potential for applications and the breakthroughs in the synthesis pathways, quantitative models possessing predictive capabilities for describing the formation and structure of these materials are still lacking. This project focuses on developing models and simulations aimed at predicting the structure and characteristics of inorganic mesoporous materials, based upon a description of the cooperative self-assembly of the surfactant and inorganic species.